Gas phase kinetics of CVD precursors

点击翻译按钮获取中文摘要

Organometallic compounds, such as ferrocene or aluminium acetylacetonate, are used to produce thin films and particles from the gas phase. For the most part, the reaction kinetics in the gas phase are not well studied, which makes rational process planning difficult or even impossible. In the first project phase, the thermal decomposition of three exemplary and important CVD precursors in the gas phase was investigated. With the help of the latest synchrotron-based mass spectrometric methods (i2PEPICO), the reaction mechanism for the conversion in inert gases could be determined much better and the first kinetic parameters were determined. The investigations took place in flow reactors, which were optimised using fluid mechanics simulations; temperature fields and residence times were also determined for microreactors using CFD simulations. In the continuation period applied for here, the reactions of the investigated CVD precursors with other reaction partners, such as water vapour, ethylene or hydrogen, are the focus of interest, as these are often used in gas-phase synthesis processes. Kinetic parameters and the reaction order of these reactions are to be investigated in a wide parameter range. Here, surrogate models are developed, which allow the adjustment and extraction of the Arrhenius parameters without the (flawed) assumption of one-dimensionality. In addition, the ratio of volume to surface area in the reactor will be systematically varied to be able to explicitly determine the share of the gas phase reactions in the reactions of the organometallic compounds. The goals are, on the one hand, to determine reliable reaction parameters and reaction mechanisms by the end of the project period and, on the other hand, to achieve methodological progress in the evaluation of kinetic data in real flows.